The invention concerns a photographic copying apparatus for the processing of photographic copy material suitable for housing in movable cassettes.
In professional photographic laboratories at the present time, photographic copies--paper images--are produced usually from photographic masters--for example, negatives--by extensively automated photographic copying machines, the so-called photographic printers. The operating personnel in the case of such machines has what are essentially monitoring functions and assures a working process that is as continuous as possible. For this purpose, the operating personnel takes care of the master material--for example negative films--and in particular must make certain that there is always sufficient copy material--unexposed photographic paper--present and that on the other hand, the exposed copy material is taken in time from the copy apparatus. In the case of modern photographic copy machines the unexposed photographic copy material is usually present as a so-called roll material, wound on a winding core in a movable light-tight storage cassette. This cassette may be hooked up on the inlet side of the photographic copy apparatus. Automatic gripping and transportation means in the copy apparatus move the copy material through the apparatus. On the outlet side, an empty winding cassette may be attached, which again is light tight and movable. The exposed copy material is automatically threaded in the winding cassette and wound onto its winding core.
Photographic copy machines with automatic copy material transportation using movable storage cassettes for the unexposed copy material and winding cassettes for the exposed material, are known from commercially available devices of this generic type. In the case of these known copy apparatuses, the operating personnel must replace empty storage and full winding cassettes in time, and a new full paper storage cassette and a new empty winding cassette must be attached as rapidly as possible in order to avoid extended downtimes of the copy apparatus. The downtime of the copy apparatus is thus essentially dependent on the reaction time of the operating personnel. Furthermore, the manual changing of cassettes is also rather time consuming. It is therefore necessary for the operating personnel to be ready for the changing of cassettes at exactly the right moment, as otherwise the copy apparatus will be down for an unnecessarily long period of time. As at the present time operators usually operate several machines simultaneously, exact timing is required which in turn requires a very high degree of attention on the part of the personnel necessary. There is little time left for the other tasks, for example, the changing of copy masters. In particular, when transferring to photographic copy machines with hourly outputs of 15,000 or more images, it is almost impossible to perform all of these tasks.
In order to remedy this disadvantage in the case of another known photographic copy apparatus, it has been proposed to mount a plurality of storage and winding cassettes both on the inlet and the outlet side of the copy apparatus on a vertical rotating disk of a separate cassette carriage. Following the emptying of a storage cassette and the filling of a winding cassette, the rotating disks are automatically rotated and a new storage cassette or winding cassette is brought into a processing position. If the cassettes are considered relatively large and heavy, it is readily apparent that this approach would require special, high performance drives for the rotating disk, which in turn must be very large and in particular would render the apparatus enormously expensive. Furthermore, in view of the relatively heavy weight of the cassettes, their mounting and fastening on the rotating disk would again render an additional expenditure necessary. The overall layout becomes very large and in particular very heavy and is very cumbersome to transport.
It is proposed in U.S. Pat. No. 4,853,742 to arrange, for example, two storage and two winding cassettes in succession at the copy material inlet and the copy material outlet side of the copy apparatus. On both the inlet and output sides, pulling means are provided on the copy apparatus that may be applied to the cassettes to draw a cassette into its processing position. To remove empty storage cassettes and full winding cassettes from the processing position, additional pushing devices acting perpendicular to the drawing means are provided. The copying apparatus described is relatively complex and expensive in its configuration. The placement in succession of at least two cassettes in each case appreciably increases the space requirements of the copying apparatus. Additional guidance and positioning means are required at the bottom for the cassettes being readied, which in case of the absence of cassettes inserted, may become a dangerous obstacle for the operating personnel. The same is even more true for the extendable and retractable tension and pushing devices at the copying apparatus.
In DE-A-3 713 171, a photographic copying apparatus is described in which two or three storage cassettes and winding cassettes are provided adjacent or in succession to each other. In the case of adjacent cassettes, it is shown that they may be located either parallel to or at an oblique angle to the direction of transport. Depending on how the cassettes are arranged relative to the direction of transport of the copy material, deflecting and guide means are provided, whereby the copy material is to be guided from each storage cassette into the direction of transport, and from said direction to the winding cassette involved. In these deflecting devices, the copy material is guided in the form of a loop in the direction required. In these deflecting and guiding devices the risk of injury to the coating of the photographic copy material is relatively high. In addition, in this copying apparatus the cassettes considerably project over the dimensions of the apparatus, so that space requirements are considerably increased. It must be assured by means of additional display means that the operator always removes the correct empty or full cassette from the cassette package and replaces it with a full or empty cassette.